Bag making device



July 12 1966 F. F. BROCKMULLER 3,260,171

BAG MAKING DEVICE Filed Aug. 8, 1963 Jn venor:

United States Patent O 3,260,171 BAG MAKING DEVICE Friedrich Franz Brockmiler, Lengerich, Westphalia, Germany, assignor to Windmller & Hlscher, Lengerich, Westphalia, Germany Filed Aug. 8, i963, Ser. No. 300,892 Claims priority, application Germany, Aug. 8, 1962,

1o Claims. (ci. 93-19) The present invention relates generally to the paper bag making art, and, more particularly, to machines for forming paper tubes by feeding a plurality of webs, gluing them together, and providing them with weakening lines; the invention concerns a further development for use between the device for providing the weakening lines and the collecting roller for super-posing the webs in order to form a multiply web, the webs having previously been provided with weakening lines and transverse stripes of adhesive.

In the manufacturing of paper bags, tube drawing machines are known wherein ya plurality of paper webs or the like are synchronously supplied and are provided with weakening lines, such as score lines or perforated lines. These weakening lines extend transversely to the direction of movement of the web, and the majority of weakening lines have portions which are longitudinally offset from each other. Thus, the portions of the weakening lines which are formed in the plurality of webs are spaced a variable distance longitudinally from imaginary center lines disposed transversely to the webs `and through the general area of weakening.

In addition to the weakening lines, -stripes of adhesive are applied to the webs transversely to the direction of movement, and the webs then pass to the collecting roller on which the webs are placed one onto the other in exact and proper alignment with the imaginary center lines disposed exactly one above the other. Furthermore, the variable spacing of the weakening lines in the individual webs results in a staggering of the web ends and the stripes of adhesive which are disposed beside the weakening lines yare eifective to join the webs together. As the webs pass through the machine, and after longitudinal stripes of adhesive are applied to the webs, they are folded in tube form, and are separated into .tubular sections having correspondingly staggered ends by pulling apart on the weakening lines, and they are then processed into bags which have flexible bottoms.

In machines of this type which are usually designed for use with a plurality of webs, for example, six webs, it has already been proposed to provide the devices for making the weakening lines and also the adhesive applying devices one above the other. When constructing the devices in this fashion, the lengths of the individual webs between the adhesive applying devices and the collecting roller are substantially the same, as are the lengths of the webs between the weakening devices and the collecting roller measured from the above-mentioned weakening center line. By this expedient, any detrimental effects resulting from variable amounts of elongation of different portions of the individual webs, and which could give rise to unequal staggering of the 'assembled webs, are avoided. Furthermore, with such a construction, all of the adhesive applying devices and all of the weakening devices together with respect to the weakening center lines cooperate in synchronism in such a manner that all of the adhesive applying devices and all of the weakening line forming devices can be -adjusted together if the machine were changed to another length of the web sections. This shortens t-he am-ount of time necessary for changing the machine.

In such machines, in order to provide for compensation of the difference in the elongation properties of the individual webs, controlling rollers are provided between the adhesive applying devices or the weakening devices, respectively, .and the collecting roller. Those controlling rollers provide for a fine adjustment of the individual lengths of the web in such a manner that the adhesive applying devices and the weakening devices are capable of operating in synchronism. Thus, in the prior art machines, .the lengths of the webs are substantially the same.

However, in these machines, there is a substantial disadvantage in that, when weakening the webs in the weakening or perforation devices, they are perforated or indented over their entire width by .perforation knives which are correspondingly offset with respect to each other at both sides of the weakening center line. At the very moment of indentation or perforation of the knives into each web, the web is very greatly stressed and with sudden changes of tension at this particular moment, there `is an increased danger that the web will be torn off at the perforation knife.

In the above-described prior art arrangement, all of the perforation knives are in engagement with the webs at the same time -and if, at this time, any sudden change in the tension should occur, this will, at first, tear off one of the webs. Because of this, the change of tension is intensified and transmitted to the remaining webs where the perforating knives are also just in engagement to perforate t-he webs. Thus, these further webs are also particularly susceptible to variations in tension and these remaining webs Iare ,also torn off subsequently to the first web which was torn off. Because of this disadvantage, the eiciency of such machines is :greatly decreased.

With these defects of the prior art in mind, it is a main object of the present invention to avoid the abovementioned disadvantages and yet lto maintain the advantages of the above-described arrangement.

Another obje-ct of the invention is to provide a device of the character described which will accomplish the functions and purposes for which it is intended in an exceedingly simple manner.

These objects and others auxiliary thereto are accomplished in accordance with preferred embodiments of the invention wherein the arrangement of the adhesive applying devices and of the weakening or perforating devices is substantially one above the other. The distance between the collecting roller and t-he adhesive applying devices is such that the lengths of the webs disposed therebetween are equal, whereas the lengths of the webs between the collecting roller and the perforating devices are unequal so .that the perforations or weakened portions are not for-med at the same time, but rather in a time staggered arrangement.

Additional o-bjects Aand advantages of the present invention will become apparent upon consideration of the following description when taken in conjunction with the accompanying drawing wherein the sole ligure is a schematic side view of an arrangement according to the insbant invention.

Before considering the drawing in detail, it should be noted that the arrangement of the adhesive applying devices and of the weakening devices in accordance with the present invention is maintained one above the other. The lengths of the individual webs between the adhesive applying devices and the collecting roller are also maintained to be substantially equal so that the adhesive applying devices operate synchronously. However, the lengths of the individual webs between the collecting roller and the perforating devices are different so that the weakening devices do not operate synchronously. While the lengths are to be different, the difference in length should not be too large, for otherwise there Will be the detrimental effect of unequal lengths of webs pointed out above. On the other hand, however, the ditference in length must be designed so that it is sufficiently large to provide an adequate interval of time between the cutting operations in the individual perforating mechanisms.

Based on practical tests which have been carried out, a feature of the present invention is that the difference in length between the longest and the shortest length of web between the weakening device and the collecting roller is maintained in the order of magnitude of the range between the shortest and the longest length of the tubular sections to which the machine may be adjusted. This adjustment may be carried out in a manner which is known per se by changing the length of web which is drawn during one rotation of the perforating knives. The circumferential speed of the knife rollers and adhesive applying means is not uniform. For example, this may be accomplished by using crank slide oscillation drives which, at the moment of providing the perforation or at the moment of the adhesive applying operation, drive the 4knives and the adhesive applicators at the web velocity.

In the event that web lengths are manufactured which are equal to the difference of the lengths selected, then two of the knives may operate synchronously during the cutting operation In such cases, the knife having the shortest distance from the collecting roller is operating at the same time as the knife having the longest distance from the collecting roller. These knives operate simultaneously and provide weakening lines at the beginning and at the end of each length of tubular section. However, this situation only arises in exceptional cases and may be accepted without any further consideration. By this means, however, the considerable advantage is obtained that the difference in length between the individual webs is not so large that there will be any differences in the extensibility or tension of the individual webs that will produce any practical deviation of the staggered spaces of the individual webs with respect to each other.

With more particular reference to the drawing, a tubular web drawing machine processing six webs is pro-- vided in which the web-lengths between the adhesive applying devices up to the collecting roller are substantially equal. However, between the weakening devices and the adhesive applying devices, the lengths of the webs are unequal.

Five of the Webs 19-23 are shown as being guided over the adhesive applying devices 14-18, respectively, and over the guide rollers 26-29, and 45-49, to the collecting roller 25. The uppermost web 24 does not pass through any adhesive applying device and is guided over the rollers 51, 52, and 5t) to the collecting roller. From this collecting roller, all of the webs together run to a tube forming station and earing off station, not shown in the drawing. The guide rollers 26-29 and 45-49 are so arranged that the lengths of the webs between the adhesive applying stations 14-18 and the collecting roller 25 are equal so that the adhesive applying devices can work synchronously. The adhesive applying devices are staggered one above the other in a direction against movement of the web in order to provide a favorable guiding of the paper web during the adhesive applying operation.

Perforation or weakening devices 3944 are disposed in front of the adhesive applying devices 14-18 and the rollers 5l and 52, and the webs pass through these devices rst. In accordance with the present invention, these perforation devices are so arranged that their distances from the collecting roller 25 are unequal. In order to provide a non-complicated manufacturing operation, the weakening devices 39-44 may be disposed vertically one above the other, as shown in the drawing. With such an arrangement, the individual web-lengths between the weakening devices 3943 and the adhesive applying devices 14-18 and therefore also between the weakening devices 39-43 and the collecting roller 25 are unequal. The length of the uppermost web 24 is also arranged so that it does not correspond to any length of the remaining webs, and this is accomplished using guide rollers 5l and 52.

The guide rollers 45-50 may, for example, be mounted to be adjustable by a slight amount in order to provide an arrangement for compensating for the differences in the staggered distances of the assembled webs due to the differences in extensibility of the webs or the tensioning thereof. The lengths `of the webs between the adhesive applying devices 11i-18 and the collecting roller 25 are exactly the same in the medium position of these guide rollers 4&5() so that substantially equal web lengths can be considered to be available between the adhesive applying devices and the collecting roller.

By the use of the arrangement as described, the simultaneous tearing off of all of the webs when sudden variations in tension occur is avoided. These variations particularly occur with quick starting of the machine and at high speeds. So, with the invention a considerable incre-'ase in the eiiiciency of the machine is achieved.

Furthermore, the danger of tearing oif a single web at the moment of engagement of the perforating knife is reduced, since the web is supported by the remaining webs in the event of sudden variations in tension, which at this moment do not affect the remaining webs.

The guide rollers 45-5, for being adjustable, are mounted in the free ends of levers 53-58 which are at their fulcrum ends connected in a manner known per se to selective turning means in order to be selectively adjustable along the arrows S9-64.

It will be understood that the above description of the present invention is susceptible to various modications, changes, and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.

What is claimed is:

l. In a bag tube making device for constructing bags from a plurality of webs of paper material or the like, the improvement which comprises: a collecting roller over which a plurality of webs may pass; a plurality of first means for applying transverse adhesive stripes to respective paper webs passing therethrough, said means all being disposed one above the other and spaced from said collecting roller to provide substantially equal lengths of the webs between said means and said roller; a plurality of second means spaced from said lirst means and all disposed in alignment one above the other for providing weakening lines transversely to the course of respective webs passing therethrough to deiine sections to be separated from the web, said second means being spaced from said collecting roller so that the length of each individual web between the collecting roller and the second means is unequal to the length of every other web therebetween.

2. The improvement defined in claim l wherein said second means are arranged so that the difference in length between the longest and shortest web between said collecting roller and said second means is of the order of magnitude of the range between the shortest and the longest length of the tubular sections to which the device may be adjusted.

3. The improvement deiined in claim 2 wherein all of said second means are disposed verticaly one above the other, and all of said first means are staggered in an inclined manner toward said second means.

4. In a bag tube making device for constructing bags from a plurality of webs of paper material or the like, the improvement which comprises: a collecting roller over which a plurality of separate webs may be collected together; a plurality of first means for applying transverse adhesive stripes to respective paper webs passing therethrough for subsequently joining the webs together in a selected manner, said means all being disposed one above the other and spaced from said collecting roller to provide substantially equal lengths of the webs between said means and said roller; a plurality of second means spaced from said first means and all disposed in alignment one above the other for providing weakening lines disposed transversely to the course of respective webs passing therethrough to deline sections to be separated from each web, said second means being spaced from said collecting roller so that the length of each individual web between the collecting roller and the second means is unequal to the length of every other web therebetween, whereby the weakening lines are provided in the respective webs at diierent times.

5. The improvement dened in claim 4 wherein all of said second means are disposed verticaly one above the other and all of said first means are staggered in an inclined manner toward said second means.

6. The improvement defined in claim 5 wherein said means and said roller are arranged so that the webs irst pass through said second means, then pass through said irst means, and then are collected together at said roller.

7. An arrangement as dened in claim 1 further comprising a plurality of guide rollers, one for each of the webs, disposed between said collecting roller and said first means for passage of each of the webs over a respective one of said guide rollers, said guide rollers being positioned to provide substantially equal web lengths between said collecting roller and said first means.

8. An arrangement as defined in claim 7 wherein at least some of said guide rollers are adjustably positioned for eliminating inequalities in the lengths of said webs between said collecting roller and said first means due to unequal extensions of the webs when subjected to tension.

9. An arrangement as dened in claim 7 wherein said plurality of irst means applies adhesive stripes to one side of each paper web and said guide rollers are arranged to bear against the other side of the webs.

10. An arrangement as delined in claim 1, further cornprising two further guide rollers disposed above said rst means for guiding the uppermost one of the plurality of webs, said further guide rollers being positioned for causing the length of the uppermost one of the plurality of webs between said collecting roller and said second means to be unequal to the length of every other web between saidcollecting roller and said second means.

References Cited by the Examiner UNITED STATES PATENTS 2,013,086 9/1935 Baker 93-14 2,897,730 8/1959 Browning 93-20 2,902,906 9/ 1959 Paul 93l9 BERNARD STICKNEY, Primary Examiner. 

4. IN A BAG TUBE MAKING DEVICE FOR CONSTRUCTING BAGS FROM A PLURALITY OF WEBS OF PAPER MATERIAL OR THE LIKE, THE IMPROVEMENT WHICH COMPRISES: A COLLECTING ROLLER OVER WHICH A PLURALITY OF SEPARATE WEBS MAY BE COLLECTED TOGETHER; A PLURALITY OF FIRST MEANS FOR APPLYING TRANSVERSE ADHESIVE STRIPES TO RESPECTIVE PAPER WEBS PASSING THERETHROUGH FOR SUBSEQUENTLY JOINING THE WEBS TOGETHER IN A SELECTED MANNER, SAID MEANS ALL BEING DISPOSED ONE ABOVE THE OTHER AND SPACED FROM SAID COLLECTING ROLLER TO PROVIDE SUBSTANTIALLY EQUAL LENGTHS OF THE WEBS BETWEEN SAID MEANS AND SAID ROLLER; A PLURALITY OF SECOND MEANS SPACED FROM SAID FIRST MEANS AND ALL DISPOSED IN ALIGNMENT ONE ABOVE THE OTHER FOR PROVIDING WEAKENING LINES DISPOSED TRANSVERSELY TO THE COURSE OF RESPECTIVE WEBS PASSING THERETHROUGH TO DEFINE SECTIONS TO BE SEPARATED FROM EACH WEB, SAID SECOND MEANS BEING SPACED FROM SAID COLLECTING ROLLER SO THAT THE LENGTH OF EACH INDIVIDUAL WEB BETWEEN THE COLLECTING ROLLER AND THE SECOND MEANS IS UNEQUAL TO THE LENGTH OF EVERY OTHER WEB THEREBETWEEN, WHEREBY THE WEAKENING LINES ARE PROVIDED IN THE RESPECTIVE WEBS AT DIFFERENT TIMES. 